Abstract: The (ZrB₂+Al₂O₃)_np/AA6016 composites with different particle contents were prepared by using Al-Zr-B-O in-situ melt reaction system.The effects of hot extrusion on the microstructure and tensile properties of the composites were studied.The microstructural studies show that the ZrB₂ and Al₂O₃ nanoparticles are subdivided into dispersed small particle clusters under hot extrusion and redistributed in the form of particle bands along the extrusion direction; the dynamic recrystallization behavior during hot extrusion can be promoted by ZrB₂ and Al₂O₃ particles, and the grain size of the composite is obviously refined after hot extrusion, the average grain size of the composite is 44.54, 10.46 μm respectively before extrusion and after extrusion.The tensile testes show that the mechanical properties of the extruded composites are optimal when the content of particles is 3 vol%.The tensile strength and elongation of the extruded composites are 398.1 MPa and 28.3%, which are increased by 28% and 12% respectively compared with those of the un-extruded composites.